1. Field of the Invention
The present invention relates to an artificial tooth with an implantable tooth root.
2. Discussion of the Prior Art
The presently known and, at this time, mostly utilized implants have their anchoring portion constituted of metal and are in the configuration of a plate, needle or screw. It is common to all of these implantable bodies that the anchoring of the prosthesis on the bone is predicated on a purely mechanical interengagement or meshing with the bone. Hereby, a direct, transitionless growing together of the implant with the bone is not possible, but it is more likely that in the bordering region between the bone and the implantable body there is presently formed a more or less thick connective tissue-like encapsulation which, upon loading of the prosthesis, increases still further in size and thickness and then produces the beginning of a rejection reaction. This process, in accordance with present scientific knowledge, can be traced back to an interaction of biochemical and biomechanical factors.
Further known are artificial tooth roots which are constituted of a metallic core with a covering of pure Al.sub.2 O.sub.3 oxide ceramic (bioinert materials). In order to increase the external surface thereof, these Al.sub.2 O.sub.3 roots are provided with cuts, ribbing structure or bores into which the jawbone is intended to grow in order to thereby produce a mechanical intermeshing. However, it has been determined that prosthesis shanks which are formed of Al.sub.2 O.sub.3 oxide ceramic, in particular under high mechanical loads in the bone/ceramic boundary region, are separated through a connective tissue capsule so as to inhibit the formation of a direct interconnection with the bone. During the course of a dynamic transformation process of the bone, this connective tissue membrane can increase in thickness at locations subjected to higher loads; thereby leading to loosening and finally the rejection or repelling of the prosthesis, respectively, the implant. Analogous objections are present against implants which are formed of other bioinert materials, among which there may be also calculated, for instance, implants formed of glass or silicon material.
In a further group of known dental prostheses, specialized glass ceramic materials are utilized as prosthesis shank which, based on their composition, are intended to exert a bioactive effect on the bone formation, by means of which it is hoped to achieve a direct growing together of the bone and of the implant. This glass ceramic and the enamel required to be adhered to metal contain materials foreign to the human body, so as to at least render questionable any long-term compatibility with the body tissue.